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ASA’s SHARC: Breakthrough Java-Based Chemical Transport Model

Posted October 28, 2008 by

One of the challenges of modeling chemicals released into the environment is accurately determining how long they will persist. With this in mind, ASA has developed methods to incorporate both systemic and local changes in environmental state in order to provide the most accurate means of determining the temporal and spatial persistence of chemicals in the environment.

ASA recently delivered v1.0 (alpha) of the System for Hazard Assessment of Released Chemicals (SHARC) to the U.S. Defense Threat Reduction Agency (DTRA). SHARC was developed as part of a Small Business Innovative Research (SBIR) project focused on the development of an advanced waterborne chemical transport modeling capability. SHARC was designed with the operational user in mind, and allows the operator to rapidly create and visualize incident characteristics and predictions from a single intuitive interface.

A chemical kinetics and fates module within SHARC incorporates available environmental information to provide thorough environmental fate determinations for a given chemical of interest. Hydrolysis is the major pathway for environmental degradation in an aqueous environment for water-reactive compounds which are moderately soluble to highly miscible. SHARC integrates chemical specific information, including solubility, density, and vapor pressure, with localized environmental variability to create a visual and analytical tool to provide the user with the ability to develop highly specific local fate scenarios. The model has the ability to calculate the hydrolysis rate instantaneously.

As with all of ASA’s systems, SHARC has a particular emphasis on near-real-time (NRT) data acquisition. As crucial as the underlying physics and chemistry is in providing realistic modeling results, the quality of the input data is a key factor. New web services-based technology allows servers to continuously evaluate different metocean data products, including winds and currents forecast data. The data services continually gather and integrate global and regional metocean datasets and make them available to operational responders on an as-needed basis. It has been shown that rapid access to present and future environmental information is essential when responding to a marine emergency.

SHARC is written in Java and represents ASA’s push to develop more applications that are compatible across different computing platforms. Java also leverages a number of open source components, including OpenMap. OpenMap is an open source JavaBeans’ GIS package developed and maintained by BBN Technologies. SHARC expands upon the base functionality provided by OpenMap by including layers and mapping tools specifically developed for viewing and manipulating both the environmental data ingested into SHARC as well as the model output. ASA has added support to OpenMap for formats such as NetCDF and Grib which are widely used in environmental sciences. SHARC also includes ASA’s TimeSlider component, which provides control over the presentation of time-varying data such as currents and the movement of chemical plumes. The system has been delivered to DTRA and is in pre-operational testing.